Page 1 R410A Commercial Air Conditioners Service Manual Series VRF V8 PRO V8i PRO MV8-252WV2RN1E(PRO) MV8i-252WV2RN1E(PRO) MV8-615WV2RN1E(PRO) MV8i-615WV2RN1E(PRO) MV8-280WV2RN1E(PRO) MV8i-280WV2RN1E(PRO) MV8-670WV2RN1E(PRO) MV8i-670WV2RN1E(PRO) MV8-335WV2RN1E(PRO) MV8i-335WV2RN1E(PRO) MV8-730WV2RN1E(PRO) MV8i-730WV2RN1E(PRO) MV8-400WV2RN1E(PRO) MV8i-400WV2RN1E(PRO) MV8-785WV2RN1E(PRO) MV8i-785WV2RN1E(PRO) MV8-450WV2RN1E(PRO) MV8i-450WV2RN1E(PRO) MV8-850WV2RN1E(PRO) MV8i-850WV2RN1E(PRO) MV8-500WV2RN1E(PRO) MV8i-500WV2RN1E(PRO) MV8-900WV2RN1E(PRO) MV8i-900WV2RN1E(PRO) MV8-560WV2RN1E(PRO) MV8i-560WV2RN1E(PRO)
Page 2 Service Manual...
Page 3: Table Of Contents
V8/V8i PRO VRF 50Hz CONTENTS Part 1 General Information ................ 3 Part 2 Component Layout and Refrigerant Circuits ........ 21 Part 3 Control .................... 38 Part 4 Field Settings ................. 61 Part 5 Electrical Components and Wiring Diagrams ....... 75 Part 6 Diagnosis and Troubleshooting .............
Page 4 V8/V8i PRO VRF 50Hz...
Page 5: Part 1 General Information
V8/V8i PRO VRF 50Hz Part 1 General Information Indoor and Outdoor Unit Capacities ............4 External Appearance................7 Outdoor Unit Combinations ..............9 Nomenclature ..................10 Combination Ratio ................14 Selection Procedure ................16...
Page 6: Indoor And Outdoor Unit Capacities
V8/V8i PRO VRF 50Hz 1 Indoor and Outdoor Unit Capacities 1.1 Indoor Units 1.1.1 Standard indoor units Table 1-1.1: Standard indoor unit abbreviation codes Abbreviation Abbreviation Type Type code code One-way Cassette High Static Pressure Duct Two-way Cassette Wall-mounted Compact Four-way Cassette Ceiling &...
Page 7 V8/V8i PRO VRF 50Hz 1.3 Outdoor Units Table 1-1.5: Outdoor unit capacity range-V8i Capacity Model Name MV8i-252WV2RN1E(PRO) 10HP MV8i-280WV2RN1E(PRO) 12HP MV8i-335WV2RN1E(PRO) 14HP MV8i-400WV2RN1E(PRO) 16HP MV8i-450WV2RN1E(PRO) 18HP MV8i-500WV2RN1E(PRO) 20HP MV8i-560WV2RN1E(PRO) 22HP MV8i-615WV2RN1E(PRO) 24HP MV8i-670WV2RN1E(PRO) 26HP MV8i-730WV2RN1E(PRO) 28HP MV8i-785WV2RN1E(PRO) 30HP MV8i-850WV2RN1E(PRO) 32HP MV8i-900WV2RN1E(PRO) Notes: 1.
Page 8 V8/V8i PRO VRF 50Hz Table 1-1.5: Outdoor unit capacity range-V8 Capacity Model Name Combination Type MV8-252WV2RN1E(PRO) MV8-280WV2RN1E(PRO) 10HP MV8-335WV2RN1E(PRO) 12HP MV8-400WV2RN1E(PRO) 14HP MV8-450WV2RN1E(PRO) 16HP MV8-500WV2RN1E(PRO) 18HP MV8-560WV2RN1E(PRO) 20HP MV8-615WV2RN1E(PRO) 22HP MV8-670WV2RN1E(PRO) 24HP MV8-730WV2RN1E(PRO) 26HP MV8-785WV2RN1E(PRO) 28HP MV8-850WV2RN1E(PRO) 30HP MV8-900WV2RN1E(PRO) 32HP MV8-960WV2RN1E(PRO) 34HP 20HP+14HP...
Page 9: External Appearance
V8/V8i PRO VRF 50Hz 2 External Appearance 2.1 Indoor Units 2.1.1 Standard indoor units Table 1-2.1: Standard indoor unit appearance One-way Cassette Two-way Cassette Compact Four-way Cassette Four-way Cassette Arc Duct Medium Static Pressure Duct High Static Pressure Duct Floor Standing Wall-mounted Ceiling &...
Page 10 V8/V8i PRO VRF 50Hz 2.3 Outdoor Units 2.3.1 V8i and Single units of V8 Table 1-2.4: V8i and Single outdoor unit of V8 appearance 8/10/12/14/16HP 18/20/22/24HP 26/28/30/32HP (with single fan) (with dual fans) (with dual fans) 2.3.2 Combinations of units of V8 Table 1-2.5: Combination outdoor unit of V8 appearance 34/36/38/40HP 42/44/46/48HP...
Page 11: Outdoor Unit Combinations
V8/V8i PRO VRF 50Hz 3 Outdoor Unit Combinations Table 1-3.1: Outdoor unit combinations Outdoor �� System capacity �� No. of branch units joint kit 25.2 ● 28.0 ● 33.5 ● 40.0 ● 45.0 ● 50.0 ● 56.0 ● 61.5 ● 67.0 ●...
Page 12: Nomenclature
○ ○ ○ ○ ○ 1 Legend Code Remarks Midea VRF indoor unit Function code H: HyperLink function Capacity index (the capacity in kW multiplied by 10) Indoor unit type Q1: One-way Cassette Q2: Two-way Cassette Q4C: Compact Four-way Cassette...
Page 13 ○ ○ ○ ○ ○ 1 Legend Code Remarks Midea VRF indoor unit Generation code 2: The 2nd generation 3: The 3rd generation Capacity index (the capacity in kW multiplied by 10) Indoor unit type Q1: One-way Cassette Q2: Two-way Cassette...
Page 14 ○ ○ ○ 1 ⑨ Legend Code Remarks Midea VRF indoor unit The 2 generation VRF DC indoor unit Capacity index (the capacity in kW multiplied by 10) Indoor unit type FA: Fresh Air Processing Unit Series category (D: DC series)
Page 15 ⑤ ⑥ ⑦ ⑧ ⑨ Legend Code Remarks Midea The 8 generation VRF Capacity index (the capacity in kW multiplied by 10) Unit category (W: VRF outdoor unit) Type (V2: All DC inverter) Power supply G:380-415V, 3N~, 50/60Hz R:380-415V, 3N~, 50Hz...
Page 16: Combination Ratio
Maximum combination ratio Minimum Type Fresh air processing Fresh air processing units and combination ratio Standard indoor units only units only standard indoor units together V8 Series outdoor 200% 1,2,3 (Single ODU) 100% 100% units 130% (Combined ODU) V8i Series...
Page 17 V8/V8i PRO VRF 50Hz Table 1-5.3: Combinations of indoor and outdoor units(V8) Outdoor unit capacity Sum of capacity indexes of Sum of capacity indexes of connected indoor Maximum number of connected indoor units (standard units (fresh air processing units and standard connected indoor Capacity index...
Page 18: Selection Procedure
V8/V8i PRO VRF 50Hz 6 Selection Procedure 6.1 Procedure Step 1: Establish design conditions Design temperature and humidity (indoor and outdoor) Required heat load of each room System peak load Piping length, level differences Indoor unit specifications (type and quantity) Step 2: Select indoor units Decide indoor unit safety factor Select indoor unit models ensuring that:...
Page 19 V8/V8i PRO VRF 50Hz 6.2 Example The following is a selection example based on total heat load for cooling. Figure 1-6.1: Room plan Room H Room G Room A Room F Room B Room E Room C Room D Step 1: Establish design conditions ▪...
Page 20 V8/V8i PRO VRF 50Hz Table 1-6.2: Extract from medium static pressure duct (T2) cooling capacity table Indoor air temperature Capacity 14°C WB 16°C WB 18°C WB 19°C WB 20°C WB 22°C WB 24°C WB Model index 20°C DB 23°C DB 26°C DB 27°C DB 28°C DB...
Page 21 V8/V8i PRO VRF 50Hz Table 1-6.5: Extract from Table 1-5.2 Combinations of Indoor and outdoor units Outdoor unit capacity Sum of capacity indexes of Maximum number of connected indoor units (standard connected indoor Capacity index indoor units only) units 50.0 250 to 650 56.0 280 to 728...
Page 22 V8/V8i PRO VRF 50Hz Find the correction factor for piping length and level difference (“K1”) Figure 1-6.3: V8 rate of change in cooling capacity K1=0.943 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 -100 -110 Notes:...
Page 23: Part 2 Component Layout And Refrigerant Circuits
V8/V8i PRO VRF 50Hz Part 2 Component Layout and Refrigerant Circuits 1 Layout of Functional Components ............22 2 Piping Diagrams ..................25 3 Refrigerant Flow Diagrams ............... 29...
Page 24 V8/V8i PRO VRF 50Hz 1 Layout of Functional Components 1.1 8-16HP layout of functional components Figure 2-1.1: 8-16HP layout of functional components Legend Parts name Compressor Oil separator High pressure switch Check value Four-way valve High pressure sensor Microchannel heat exchanger Electronic expansion valve (EEVA) Stop valve(gas side) Stop valve(liquid side)
Page 25 V8/V8i PRO VRF 50Hz 1.2 18-24HP layout of functional components Figure 2-1.2: 18-24HP layout of functional components Legend Parts name Compressor Oil separator High pressure switch Check value Four-way valve High pressure sensor Microchannel heat exchanger Electronic expansion valve (EEVA) Stop valve(gas side) Stop valve(liquid side) Electronic expansion valve (EEVC)
Page 26 V8/V8i PRO VRF 50Hz 1.3 26-32HP layout of functional component Figure 2-1.3: 26-32HP layout of functional components Legend Parts name Compressor Oil separator High pressure switch Check value Four-way valve High pressure sensor Microchannel heat exchanger Electronic expansion valve (EEVA) Stop valve(gas side) Stop valve(liquid side) Electronic expansion valve (EEVC)
Page 27 V8/V8i PRO VRF 50Hz 2 Piping Diagrams 2.1 8-16HP piping diagram Figure 2-2.1: 8-16HP piping diagram Legend Parts name Parts name Compressor Charge port Oil separator Low pressure sensor High pressure switch Gas-liquid separator Check value Muffler Four-way valve Heat exchanger High pressure sensor Sensor Code Description...
Page 28 V8/V8i PRO VRF 50Hz 2.2 18-24HP piping diagram Figure 2-2.2: 18-24HP piping diagram Legend Parts name Parts name Compressor Charge port Oil separator Low pressure sensor High pressure switch Gas-liquid separator Check value Muffler Four-way valve Heat exchanger High pressure sensor Sensor Code Description Heat exchanger deicer temperature sensor...
Page 29 V8/V8i PRO VRF 50Hz 2.3 26-32HP piping diagram Figure 2-2.3: 26-32HP piping diagram Legend Parts name Parts name Compressor Low pressure sensor Oil separator Gas-liquid separator High pressure switch Muffler Check value Heat exchanger Four-way valve Refrigerant bypass solenoid valve (SV6) High pressure sensor Sensor Code Description...
Page 30 V8/V8i PRO VRF 50Hz 2.4 Key components 1. Oil separator: Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation efficiency is up to 99%. 2. Gas-liquid separator: Separates liquid refrigerant from gas refrigerant, stores liquid refrigerant and oil to protect compressor from liquid hammering.
Page 31 V8/V8i PRO VRF 50Hz Refrigerant Flow Diagrams 3.1 8-16HP 3.1.1 Cooling operation Figure 2-3.1: 8-16HP refrigerant flow during cooling operation 3.1.2 Heating operation Figure 2-3.2: 8-16HP refrigerant flow during heating operation...
Page 32 V8/V8i PRO VRF 50Hz 3.1.3 Oil return operation in cooling mode Figure 2-3.3: 8-16HP refrigerant flow during oil return operation in cooling mode 3.1.4 Oil return operation in heating mode and defrosting operation (4-way valve change direction) Figure 2-3.4: 8-16HP refrigerant flow during oil return operation in heating mode and defrosting operation (4-way valve change direction)
Page 33 V8/V8i PRO VRF 50Hz 3.1.5 Oil return operation in heating mode (4-way valve keep in the same direction) Figure 2-3.5: 8-16HP refrigerant flow during oil return operation in heating mode (4-way valve keep in the same direction)
Page 34 V8/V8i PRO VRF 50Hz 3.2 18-24HP 3.2.1 Cooling operation Figure 2-3.6: 18-24HP refrigerant flow during cooling operation 3.2.2 Heating operation Figure 2-3.7: 18-24HP refrigerant flow during heating operation...
Page 35 V8/V8i PRO VRF 50Hz 3.2.3 Oil return operation in cooling mode Figure 2-3.8: 18-24HP refrigerant flow during oil return operation in cooling mode 3.2.4 Oil return operation in heating mode and defrosting operation (4-way valve change direction) Figure 2-3.9: 18-24HP refrigerant flow during oil return operation in heating mode and defrosting operation (4-way valve change direction)
Page 36 V8/V8i PRO VRF 50Hz 3.2.5 Oil return operation in heating mode (4-way valve keep in the same direction) Figure 2-3.10: 18-24HP refrigerant flow during oil return operation in heating mode (4-way valve keep in the same direction)
Page 37 V8/V8i PRO VRF 50Hz 3.3 26-32HP 3.3.1 Cooling operation Figure 2-3.11: 26-32HP refrigerant flow during cooling operation 3.3.2 Heating operation Figure 2-3.12: 26-32HP refrigerant flow during heating operation...
Page 38 V8/V8i PRO VRF 50Hz 3.3.3 Oil return operation in cooling mode Figure 2-3.13: 26-32HP refrigerant flow during oil return operation in cooling mode 3.3.4 Oil return operation in heating mode and defrosting operation (4-way valve change direction) Figure 2-3.14: 26-32HP refrigerant flow during oil return operation in heating mode and defrosting operation (4-way valve change direction)
Page 39 V8/V8i PRO VRF 50Hz 3.3.5 Oil return operation in heating mode (4-way valve keep in the same direction) Figure 2-3.15: 26-32HP refrigerant flow during oil return operation in heating mode (4-way valve keep in the same direction)
Page 40: Part 3 Control
V8/V8i PRO VRF 50Hz Part 3 Control 1 General Control Scheme Flowchart ............39 2 Stop Operation ..................40 3 Standby Control ..................41 4 Startup Control ..................41 5 Normal Operation Control ............... 44 6 Protection Control ................... 50 7 Special Control ..................
Page 41: General Control Scheme Flowchart
V8/V8i PRO VRF 50Hz 1 General Control Scheme Flowchart Sections 2 to 8 on the following pages detail when each of the controls in the flowchart below is activated. Stop operation ▪ Abnormal shutdown ▪ System stops ▪ A unit stops when the load demanded decreases Standby control Special control ▪...
Page 42: Stop Operation
V8/V8i PRO VRF 50Hz 2 Stop Operation The stop operation occurs for one of the three following reasons: Abnormal shutdown: in order to protect the compressors, if an abnormal state occurs，the system will makes a 'stop with thermos-off' operation and an error code will be displayed on the outdoor unit digital displays. The system stops when the set temperature of all indoor unit has been reached, or all indoor units has stop or error.
Page 43: Standby Control
V8/V8i PRO VRF 50Hz 3 Standby Control 3.1 Crankcase Heater Control The crankcase heater is used to prevent refrigerant from mixing with compressor oil when the compressors are stopped. The crankcase heater is controlled mainly according to the minimum of discharge temperatures. When the minimum of discharge temperatures is above 45°C, the crankcase heater is off;...
Page 44 V8/V8i PRO VRF 50Hz 4.3 Startup Control for Cooling Operation Table 3-4.1: Component control during startup in cooling mode Startup control Wiring Before Component startup STEP1 STEP2 STEP3 STEP4 STEP5 diagram label Inverter compressor INV1 Initial step for 30S, adjust according to the high then+8Hz×Nodu / 10S.
Page 45 V8/V8i PRO VRF 50Hz 4.4 Startup Control for Heating Operation Table 3-4.2: Component control during startup in heating mode Startup control Wiring Before Component startup STEP1 STEP2 STEP3 STEP4 STEP5 diagram label Inverter compressor INV1 Initial step for 30S, Adjust according to then+8Hz×Nodu / 10S.
Page 46: Normal Operation Control
V8/V8i PRO VRF 50Hz 5 Normal Operation Control 5.1 Component Control during Normal Operation Table 3-5.1: Outdoor unit component control during normal operation Wiring Component Cooling Heating diagram label PI control, High pressure protection, Low pressure Inverter compressor A COMP(A) protection, Discharge temperature protection, Inverter Over-current protection control, Inverter module temperature protection control, Wet compression...
Page 47 V8/V8i PRO VRF 50Hz 5.2 Compressor Control Cooling operation Compressor frequency is PI controlled to keep low pressure at target temperature. Te: Low pressure equivalent saturation temperature (°C) Tes: Target Te value. Tes will be decided by Te setting, if you choose Auto that means except Te setting, the Tes would be adjusted according to the ambient temperature, refrigerant pipe length, etc.
Page 48 V8/V8i PRO VRF 50Hz 5.3 Rotation of Compressors In order to make operating time equal for each compressor of combination outdoor units, outdoor units are used in rotation. Figures 3-5.1 to 3-5.2 show the compressor rotation in systems with two and three units. The master unit and slave units 1 and 2 are shown from left to right in that order, and the circled numbers ( ①,②,③,④,⑤,⑥...
Page 49 V8/V8i PRO VRF 50Hz 5.5 Electronic Expansion Valve Control 5.5.1EEVA control The positions of electronic expansion valves EEVA are controlled in steps from 0/0 (fully closed) to 480/2880 (fully open). 5.5.1.1 Outdoor unit heat exchanger is performed via the evaporator when outdoor temperature ≥- 8°C：...
Page 50 V8/V8i PRO VRF 50Hz 5.6 Outdoor Fan Control The speed of the outdoor unit fans is adjusted in steps, as shown in Table 3-5.9 Table 3-5.9: Outdoor fan speed steps Fan speed (rpm) Note Fan speed 18-24HP 26-32HP cooling heating index 8-16HP Stop operation, Startup...
Page 51 V8/V8i PRO VRF 50Hz Table 3-5.10 Upper limit fan step in static pressure mode Cooling Static Pressure mode 0Pa(default) 20Pa 40Pa 60Pa 80Pa 100Pa 120Pa Heating Static Pressure mode 0Pa(default) 20Pa 40Pa 60Pa 80Pa 100Pa 120Pa Note: Standard models can provide 20Pa maximum external static pressure. High static pressure models can provide 120Pa maximum external static pressure. If the external static pressure you needed over 20Pa, please contact us by suppliers for customized high static pressure models.
Page 52: Protection Control
V8/V8i PRO VRF 50Hz 6 Protection Control 6.1 High Pressure Protection Control This control protects the system from abnormally high pressure and protects the compressors from transient spikes in pressure. Figure 3-6.1: High pressure protection control Normal operation 4.15MPa < 3.5MPa ≥...
Page 53 V8/V8i PRO VRF 50Hz 6.4 Over-current Protection Control Over current protection control is performed to prevent tripping due to transient inverter over-current. It protects the compressors from abnormally high currents. It is performed for each compressor. Figure 3-6.6: Over-current protection control Normal operation Current Current...
Page 54 V8/V8i PRO VRF 50Hz 6.5 Ambient temperature out of range protection control When the outdoor ambient temperature rises above 30.5°C heating mode is disabled to prevent the mechanical load on compressors becoming too high and to prevent low compression ratios which can result in insufficient compressor internal oil lubrication.
Page 55 V8/V8i PRO VRF 50Hz 6.6.2 Error code F63 Figure 3-6.10: Non-inductance resistors temperature protection control Normal operation 95°C Tr <70°C ≥ Non-inductance resistors temperature protection, error code F63 is displayed Notes: Tr: Non-inductance resistors temperature 6.7 Wet Compression Protection Control This protection is used to prevent compressor from damaging for the long time wet compression so that it can’t be lubricated well.
Page 56: Special Control
V8/V8i PRO VRF 50Hz 7 Special Control 7.1 Oil Return Operation In order to prevent compressors from running out of oil, the oil return operation is conducted to recover oil that has flowed out of the compressor(s) and into the piping system. This operation is performed for all units including units that are in standby.
Page 57 V8/V8i PRO VRF 50Hz Cooling indoor unit 500P EEV Thermo ON unit Thermo OFF unit Keep the previous fan speed Stop or Fan Thermo ON unit Superheat control Electronic expansion valve (EEV) Thermo OFF unit 80pls Stop or Fan 80pls 7.1.2 Heating Oil Return Control It’s basically identical with defrosting operation, refer to 7.2 Defrosting Operation...
Page 58 V8/V8i PRO VRF 50Hz 7.2 Defrosting Operation In order to recover heating capacity, the defrosting operation is conducted when the outdoor unit heat exchanger is performing as an evaporator. The defrosting operation is controlled according to outdoor ambient temperature, outdoor heat exchanger temperature, indoor heat exchanger temperature and outdoor units running time.
Page 59 V8/V8i PRO VRF 50Hz Defrosting control time is no less than 135Sec and fulfill one of the conditions below: ▪ Pc-max ≥ 3.0MPa. ▪ Total defrosting control time has reached 9 minutes. ▪ T3_min >Target value for a certain time. Table 3-7.4: Indoor unit component control during defrosting operation Heating indoor unit (ODU operates cooling main operation) 500PEEV...
Page 60: Other Control
V8/V8i PRO VRF 50Hz 8 Other Control 8.1 Overload control Overload control is used to maintain comfort requirement (i.e. outlet air temperature) and keep proper system pressure. Figure 3-8.1: Overload control Normal operation Indoor unit operation ratio <105% Indoor unit operation ratio 130% ≥...
Page 61 V8/V8i PRO VRF 50Hz 8.3 Auto Snow-blowing Control Auto snow-blowing control is used to prevent the fans of stopped outdoor units from destroying by heavy snow. Timing of auto snow-blowing operation: T4≤3°C and outdoor units stops time elapse for TA. Table 3-8.3: Snow-blowing control TA: Level a TA: Level b...
Page 62 V8/V8i PRO VRF 50Hz Table 3-8.4: Low noise mode(continue) Silent mode 8 Silent mode 9 Silent mode 10 Silent mode 11 Silent mode 12 Silent mode 13 Silent mode 14 Max. Max. Max. Max. Max. Max. Max. Max. Max. Max. Max.
Page 63: Part 4 Field Settings
V8/V8i PRO VRF 50Hz Part 4 Field Settings Overview ..................... 62 Digital display and button settings ............62 System Parameter Check ..............72...
Page 64 V8/V8i PRO VRF 50Hz 1. Overview This chapter describes how the system configuration can be implemented once the installation is completed, and other relevant information. It contains the following information: ⚫ Implement field settings ⚫ Using the Check function 2. Digital display and button settings 2.1 Digital display output Table 4-2.1: Digital display output Outdoor unit state...
Page 65 V8/V8i PRO VRF 50Hz 2.3 Menu mode Only master unit has the full menu functions, slave units only have error codes check and cleaning functions. 1. Long press SW5 "MENU" button for 5 seconds to enter menu mode, and the digital display displays "n0". 2.
Page 66 V8/V8i PRO VRF 50Hz Menu mode function: Table 4-2.3 Menu mode function: First level menu Second level menu Specified menu mode Description Default Query History error (last ten error codes) (History error) Cleaning history error Query Indoor unit's address (Information (address) Query the address of Indoor unit in power-off condition query)
Page 67 V8/V8i PRO VRF 50Hz Table 4-2.3 Menu mode function(continue) First level menu Second level menu Specified menu mode Description Default Silent mode 8 Silent mode 9 Silent mode 10 Silent mode 11 (Silent mode) Silent mode 12 Silent mode 13 Silent mode 14 √...
Page 68 V8/V8i PRO VRF 50Hz Table 4-2.3 Menu mode function(continue) First level menu Second level menu Specified menu mode Description Default 0m level difference between indoor unit and outdoor unit √ 20m level difference between indoor unit and outdoor unit 40m level difference between indoor unit and outdoor unit 2[1] 60m level difference between indoor unit and outdoor unit (Level difference)
Page 69 V8/V8i PRO VRF 50Hz Table 4-2.3 Menu mode function(continue) First level menu Second level menu Specified menu mode Description Default -3°C 0°C 3°C 6°C √ (target evaporation 7°C temperature of the 8°C indoor unit) 9°C (evaporation 10°C 11°C condensation 41°C temperature) 42°C 43°C...
Page 70 V8/V8i PRO VRF 50Hz 2.4 Special mode introduction 2.4.1 Priority mode setting Priority mode can only be set on the master unit. When an indoor unit is in mode conflict with the outdoor units the unit displays the mode conflict error. The digital display on indoor main PCB will display error code E0. There are ten priority mode options: 1.
Page 71 V8/V8i PRO VRF 50Hz 5. Changeover mode: Before using this mode, you need to set the VIP indoor unit address. The default VIP address is 63, the VIP address also can be changed through menu mode“n1-6”. In changeover mode, if the VIP indoor unit is operating, the outdoor units will operate in the mode of the VIP indoor unit.
Page 72 V8/V8i PRO VRF 50Hz Step1:preparation Step2:Calculate static pressure of Outdoor unit Step3:Indoor and outdoor Display error code temperatures are within the allowable U32/U33/U34 range of test run The number of Indoor units Turn on all indoor units is greater than 4 Start the Indoor unit with singular address Step4:The stop valve has been opened...
Page 73 V8/V8i PRO VRF 50Hz 3. System refrigerant quantity detection After entering this mode, the system will automatically run and finally output the diagnostic results of the system refrigerant quantity. Diagnostic results: Normal: Digital display “d34” Significantly excessive: Digital display “d32” Excessive: Digital display “d33”...
Page 74 V8/V8i PRO VRF 50Hz 3. System Parameter Check 3.1 UP / DOWN system check button Before pressing UP or DOWN button, allow the system to operate steadily for more than an hour. On pressing UP or DOWN button, the parameters listed in below table will be displayed in sequence. Table 4-3.1 system check list: DSP1 content Parameters displayed on DSP2...
Page 75 V8/V8i PRO VRF 50Hz Table 4-3.1 system check list(continue): DSP1 content Parameters displayed on DSP2 Remarks 27.-- Discharge superheat degree (°C) Actual value = value displayed 28.-- Primary current(A) Actual value = value displayed /10 29.-- Inverter compressor A current (A) Actual value = value displayed /10 30.-- Inverter compressor A current (A)
Page 76 V8/V8i PRO VRF 50Hz Table 4-3.1 system check list(continue): DSP1 content Parameters displayed on DSP2 Remarks 50.-- Capacity of heating mode IDUs (HP) Actual value = value displayed 【0】:No result 【1】:Significantly insufficient 【2】:insufficient Refrigerant volume judgment 【3】:Normal 51.-- 【4】:excessive 【5】:Significantly excessive Dirty blockage rate 52.-- 0~10, 10 represents the worst...
Page 77: Part 5 Electrical Components And Wiring Diagrams
V8/V8i PRO VRF 50Hz Part 5 Electrical Components and Wiring Diagrams Outdoor Unit Electric Control Box Layout ..........76 Outdoor Unit Main Control Board ............77 Compressor & Fan drive board ............. 81 Wiring Diagrams .................. 88...
Page 78: Outdoor Unit Electric Control Box Layout
V8/V8i PRO VRF 50Hz 1. Outdoor Unit Electric Control Box Layout 1.1 8-16HP electric control box 1.2 8-16HP electric control box Figure 5-1.1: 8-16HP electric control box 1.3 18-32HP electric control box Figure 5-1.2: 18-32HP electric control box Notes: The differences between electric control box of 18-32HP and 8-16HP are shown in the Figure 5-1.2. Others are the same as 8-16HP electric control box.
Page 79: Outdoor Unit Main Control Board
V8/V8i PRO VRF 50Hz Outdoor Unit Main Control Board 2.1 Outdoor unit main Control Board ports Figure 5-2.1: Outdoor unit main Control Board ports Notes: Label descriptions are given in Table 5-2.1: Main Control Board port...
Page 80 V8/V8i PRO VRF 50Hz Table 5-2.1: Main Control Board port Label in Figure Port code Content Port voltage 5-2.1 CN82 Reserved 5Vdc CN36 Recirculation fan control port 3.3Vdc CN70 EEVA drive port 12Vdc CN71 EEVB drive port(Reserved) 12Vdc CN72 EEVC drive port 12Vdc CN73 EEVE drive port...
Page 81 V8/V8i PRO VRF 50Hz 2.2 Outdoor unit main Control Board components 2.2.1 Layout Figure 5-2.2: Outdoor unit main Control Board components 2.2.2 Function of buttons SW3 to SW6 Table 5-2.2: Function of buttons SW3 to SW6 Button Function In menu mode: previous and next buttons for SW3 (UP) menu modes.
Page 82 V8/V8i PRO VRF 50Hz 2.2.3 Digital display output Table 5-2.4: Digital display output in different operating states Outdoor unit state Parameters displayed on DSP1 Parameters displayed on DSP2 The number of indoor units in DSP1 Standby The address of outdoor unit communication with the outdoor units For single...
Page 83: Compressor & Fan Drive Board
V8/V8i PRO VRF 50Hz Compressor & Fan drive board 3.1 Corresponding table of Compressor & Fan drive board and outdoor units Table 5-2.5: Corresponding table of Compressor & Fan drive board and outdoor units Compressor & Fan drive board model Outdoor unit series Model V8 PRO...
Page 84 V8/V8i PRO VRF 50Hz 3.2 Compressor & Fan drive board of 50A Figure 5-2.3: Compressor & Fan drive board of 50A...
Page 85 V8/V8i PRO VRF 50Hz 3.3 Compressor & Fan drive board of 35A Figure 5-2.4: Compressor & Fan drive board of 35A...
Page 86 V8/V8i PRO VRF 50Hz 3.4 Compressor & Fan drive board ports Figure 5-2.5: Compressor & Fan drive board ports of 50A Table 5-2.6: Compressor & Fan drive board port Label in Port Feature Content Port voltage Figure 5-2.5 code identifier Positive pole Input terminal of the high voltage capacitors P-in 438Vdc-650Vdc(Rated at 540Vdc)
Page 87 V8/V8i PRO VRF 50Hz Label in Port Feature Content Port voltage Figure 5-2.5 code identifier Power supply terminal for DC fan drive board (P,N) 438Vdc~650Vdc(Rated 540Vdc; CN38 (Reserved） P is positive, N is negative) CN26 Fan module controls power supply(Reserved） DCFAN Three phase output of the inverter ,connected to the DC fan 0~100%*input voltage(varying)
Page 88 V8/V8i PRO VRF 50Hz 3.5 The installation guide of Compressor & Fan drive board Figure 5-2.6: The installation guide of Compressor & Fan drive board...
Page 89 V8/V8i PRO VRF 50Hz 1. Before maintaining or repairing the outdoor unit, cut off the power supply of the outdoor unit for 5 minutes and use a mustimeter to ensure that the voltage is zero to avoid electric shock. Notice The unit has the low-power standby function. After entering this mode, only the power indicator of the main board is on.
Page 90: Wiring Diagrams
V8/V8i PRO VRF 50Hz 4. Wiring Diagrams Figure 5-3.1: V8 outdoor unit wiring diagram...
Page 91: Part 6 Diagnosis And Troubleshooting
V8/V8i PRO VRF 50Hz Part 6 Diagnosis and Troubleshooting 1 Error Code Table ..................90 2 Error in Main Control................95 3 Error in Compressor Driver ..............172 4 Error in Fan Drive ................... 182 5 Appendix ....................191...
Page 92 V8/V8i PRO VRF 50Hz 1 Error Code Table 1.1 Outdoor Error code table Table 6-1.1 Outdoor Error code table Manual re-start Error code Error description Remarks required Outdoor unit’s Emergency shutdown fault Outdoor unit’s No.x Inverter driver board does not match the main control board fault xA61 No.x slave unit error...
Page 93 V8/V8i PRO VRF 50Hz Manual re-start Error code Error description Remarks required Gas pipe temperature sensor (Tg) error (open/short) sensor error Liquid pipe temperature sensor (T5) error (open/short) sensor error Outdoor Heat exchanger gas temperature sensor (T8) error (open/short) sensor error Outdoor heat exchanger liquid temperature sensor (TL) error (open/short) sensor error xFd1...
Page 94 V8/V8i PRO VRF 50Hz Manual re-start Error code Error description Remarks required EEPROM error E party error Overcurrent HyperLink overcurrent error protection Anti-condensation protection condensation Pd1 protection occurs 2 times in 60 minutes condensation missing 1b01 Electronic expansion valve (EEVA) error Connection missing 2b01...
Page 95 V8/V8i PRO VRF 50Hz 1.3 Compressor drive error code table Table 6-1.3 Compressor drive error code table Manual re-start Error code Error description Remarks required xL1E Hardware overcurrent current overload xL11 Software overcurrent error xL12 Software overcurrent protection last 30s Over-temperature xL2E Module overtemperature protection...
Page 96 V8/V8i PRO VRF 50Hz 1.5 Status prompt code table Table 6-1.5 Status prompt code table Manual re-start Status code Code description Remarks required2 Oil return,”x” is the current step node Status hint Defrost, ”x” is the current step node Status hint The outdoor ambient temperature exceeds the upper limit Status hint (Heating mode)
Page 97 V8/V8i PRO VRF 50Hz 2 Error in Main Control 2.1 A01: emergency shutdown of Outdoor Units Digital display output Description ▪ Compressor protection shut down ▪ All Outdoor Units stop running ▪ Error codes are displayed only on master uint. Trigger / recover condition (1)Check menu N28 = 0: ▪...
Page 98 V8/V8i PRO VRF 50Hz Menu option NC0=3 or NC1=3? Menu option N28=0? CN55/CN56 short CN55/CN56 open circuit circuit Rule out short Rule out open circuit condition circuit condition Automatic recovery Error in the main after 5s? control board Replace the main- control board troubleshooting...
Page 99 V8/V8i PRO VRF 50Hz 2.2 xA61: No.x slave unit error Digital display output Description ▪ xA6 shows The Outdoor Unit at address X is in error(x=1,2,3) ▪ All Outdoor Units stop running ▪ Error code are displayed only on master unit. Trigger / recover condition ▪...
Page 100 V8/V8i PRO VRF 50Hz 2.3 AAx: Inverter driver board X does not match the main control board Digital display output Description ▪ No.x Inverter driver board does not match the main control board ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 101 V8/V8i PRO VRF 50Hz 2.4 xb53: No.x Recirculation fan error Digital display output Description ▪ No.x Recirculation Fan[1] is in error ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 102 V8/V8i PRO VRF 50Hz Procedure xb53 Check whether the rewring wiring is correct[2] Two Recirculation The original faulty Fan system fan is normal Check whether the faulty fan works properly after the cables are exchanged with the normal fan Replace the power supply board Power on again, fan Replace the fan...
Page 103 V8/V8i PRO VRF 50Hz 2.5 bA1: HyperLink cannot open or close IDU’s Electronic expansion valve Digital display output Description ▪ When some IDUs are powered off, HyperLink fail to close their EEV. ▪ All units stop running. ▪ Error code is only displayed on the master unit Trigger / recover condition ▪...
Page 104 V8/V8i PRO VRF 50Hz Procedure Replace the communication cable HyperLink Diameter of with the diameter specified in the communication line＜1.5mm2 installation manual Add a repeater at the The total length of HyperLink communication place 200 communication cables exceeds meters from the outside 200 meters without a repeater machine to the inside machine Connect the communication line of...
Page 105 V8/V8i PRO VRF 50Hz 2.6 U38: Outdoor Unit has no address. Digital display output Description ▪ Outdoor Unit has no address. ▪ The ODU with error can not run. ▪ The master outdoor unit cannot communicate with indoor units. Trigger / recover condition ▪...
Page 106 V8/V8i PRO VRF 50Hz 2.7 C13: The address of Outdoor Unit is repeated Digital display output Description ▪ The address of Outdoor Unit is repeated. Trigger /recover condition ▪ Trigger:Two or more outdoor units in the Combined system have the same address ▪...
Page 107 V8/V8i PRO VRF 50Hz 2.8 C21: Communication error between IDU and ODU. Digital display output Description ▪ Communication error between IDU and ODU ▪ All units stop running. ▪ Error code is only displayed on the master unit. Trigger / recover condition ▪...
Page 108 At least one 2rd IDU exists in the system Non-V8 communication protocol RS-485 (P Q E) All the existing IDUs in the system are V8 series and Use PQ communication port and enter N45-0 to choose V8 use Hyper-Link communication protocol...
Page 109 V8/V8i PRO VRF 50Hz 2.9 C26 Abnormal reduction in the number of indoor units Digital display output Description ▪ The number of online indoor units is smaller than the configured number ▪ All units stop running. ▪ Error code is only displayed on the master unit Trigger / recover condition ▪...
Page 110 V8/V8i PRO VRF 50Hz Procedure Power on the IDUs again and check "Number of online units" after 6 minutes of standby[1] Check whether the number There are IDUs Check the power cord of the IDUs, and of online IDUs is consistent with not powered on in set the address for the IDU by the setting number...
Page 111 V8/V8i PRO VRF 50Hz 2.10 C28: Abnormal increase in the number of indoor units Digital display output Description ▪ Abnormal increase in the number of indoor units ▪ All units stop running. ▪ Error code is only displayed on the master unit Trigger / recover condition ▪...
Page 112 V8/V8i PRO VRF 50Hz Procedure Power on the ODU again and check "Number of Remove IDUs of other systems online units" after 6 minutes of standby[1] whether the number of online Check whether other The ODU mainboard is damaged. IDU is consistent with the actual IDUs are connected to Replace the mainboard number of connected IDU...
Page 113 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The No.x outdoor slave unit cannot communicate with the outdoor master unit. ▪ All units stop running. ▪ Error code is only displayed on the slave unit with the error. Trigger / recover condition ▪...
Page 114 V8/V8i PRO VRF 50Hz Check whether the address Enter the menu N40 to reset of the ODU is correct[1] the outdoor unit address[1] Check whether the communication cable Reconnect the between ODUs are correct and secure communication lines Dismantle the H1/H2/E communication line Check whether the DC voltage between H1-E and H2-E of...
Page 115 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The number of online slave outdoor units detected by the master outdoor unit decreases ▪ All units stop running. ▪ Error code is only displayed on the master unit Trigger / recover condition ▪...
Page 116 V8/V8i PRO VRF 50Hz Different series or Check whether the OSUs independent units can not be support parallel system mixed use, reinstall Make sure all outdoor units are Check whether the power connected to correct power supply of ODU is normal suppliess Check whether the address Enter the menu N40 to reset...
Page 117 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The number of online outdoor slave units detected by the outdoor master unit increases ▪ All units stop running. ▪ Error code is only displayed on the master unit Trigger / recover condition ▪...
Page 118 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The communication between the main control board and No.x inverter driver board is error ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 119 V8/V8i PRO VRF 50Hz Digital display output Error code Error description Remarks Digital display output Outdoor ambient temperature sensor sensor error (T4) error(open/short) Microchannel heat exchanger outlet temperature sensor(T6B) sensor error error(open/short) Main heat exchanger pipe temperature sensor error sensor (T3) error(open/short) Microchannel heat exchanger inlet temperature sensor(T6A) sensor error...
Page 120 V8/V8i PRO VRF 50Hz ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪ Trigger condition:The main control board cannot obtain the normal AD value of the temperature sensor ▪...
Page 121 V8/V8i PRO VRF 50Hz Digital display output Description ▪ All units stop running ▪ Error code is displayed on the unit with the error. Trigger/ Recover condition ▪ Trigger condition: F62: The NTC temperature inside the compressor board or fan module is higher than 100 ° C F6A: F62 protection occurs 3 times in 100 minutes ▪...
Page 122 V8/V8i PRO VRF 50Hz Procedure F62，F6A Power on again, Screws on the module Refastening board are not secured screw[1] troubleshooting？ Brush a layer of thermal grease Check whether the Power on again, evenly[2], and thermal grease layer is tighten the screws troubleshooting？...
Page 123 V8/V8i PRO VRF 50Hz 2.17 F63: Non-inductive resistance Tr overtemperature protection Digital display output Description ▪ All units stop running ▪ Error code is displayed on the outdoor unit with the Error Trigger/ Recover condition ▪ Trigger condition: The non-inductive resistance temperature exceeds 95 ° C ▪...
Page 124 V8/V8i PRO VRF 50Hz Procedure The Recirculation Fan Top Flow Series in the electric control box works improperly The air intake grille at the bottom of the machine or the internal air duct removal of fault refer to is blocked the procedure of xb53 Clean up Power on again, and...
Page 125 V8/V8i PRO VRF 50Hz 2.18 F72, F7A: Discharge Temperature protection Digital display output Description ▪ Discharge Temperature is over the limit. ▪ All outdoor Unit stop running ▪ Error code is displayed on the unit with the error Trigger / Recover condition ▪...
Page 126 V8/V8i PRO VRF 50Hz Procdure F72/F7A .Discharge temperature Reconnect the sensor sensors' connections on main to the Main control control board are loose[1] board Error disappear Troubleshooting The temperature sensor Replace the is abnormal[2] temperature sensor check whether there is a big The main control board difference between the measured is damaged.
Page 127 V8/V8i PRO VRF 50Hz 2.19 F75: Compressor discharge insufficient superheat protection Digital display output Description ▪ Superheat degree of Compressor discharge temperature is too low, triggering protection shutdown ▪ Determination during operation of outdoor unit. ▪ All units stop running. ▪...
Page 128 V8/V8i PRO VRF 50Hz Procedure The Discharge Ensure that the Discharge temperature temperature sensor is not sensor is properly connected and located at properly connected [1] the top of the compressor Discharge temperature Replace the sensor sensor failure [2] Replacing the high High pressure sensor failure[3] pressure Sensor Replace the...
Page 129 V8/V8i PRO VRF 50Hz 2.20 P11: High pressure sensor error Digital display output Description ▪ Open/short circuit error of high pressure sensor ▪ All units stop running. ▪ The error code is displayed on the Outdoor Unit with error. Trigger / recover condition ▪...
Page 130 V8/V8i PRO VRF 50Hz 2.21 P12/P14:High pressure protection Digital display output Description ▪ P12: The high pressure is over the limit. ▪ P14: 3 times P12 in 100 minutes ▪ All units stop running ▪ Error code is displayed on the unit with the Error Trigger / recover condition ▪...
Page 131 V8/V8i PRO VRF 50Hz Procedure The stop valves are close Open the stop valves 1. Connect pressure gauge to test Discharge pressure 2. Power on and run again, and check the low pressure value Check whether the pressure Discharge part of the refrigerant. Add sensor is normal[1] oil if it leaks during discharge Compare the pressure...
Page 132 V8/V8i PRO VRF 50Hz 2.22 P13: High pressure switch protection Digital display output Description ▪ All units stop running ▪ Error code is displayed on the unit with the Error Trigger / recover condition ▪ Trigger condition: discharge pressure≥ 4.2MPa. ▪...
Page 133 V8/V8i PRO VRF 50Hz Procedure Ensure th e following 3 points: 1. Th e stop valve has been opened 2. Th e pressure switch is properly connected to the compressor module board 3. Th e pressure switch is in normal conduction state Th e 3 points above is normal Correct and reconfirm...
Page 134 V8/V8i PRO VRF 50Hz 2.23 P21: Low pressure sensor error Digital display output Description ▪ Open/short circuit Error in suction pressure sensor ▪ All units stop running. ▪ Error code is only displayed on the slave unit with the error. Trigger / recover condition ▪...
Page 135 V8/V8i PRO VRF 50Hz Procedure Check whether the sensor is Reconnect Sensor according properly and securely connected to the wiring diagram to the mainboard 1.Use pressure gauge to measure the low pressure 2. Use multimeter to measure the pressure sensor output voltage Whether the measured pressure value and output voltage Replace the...
Page 136 V8/V8i PRO VRF 50Hz 2.24 P22, P25: Low pressure protection Digital display output Description ▪ All units stop running. ▪ Error code is displayed on the unit with the error. Trigger/ Recover condition ▪ Trigger condition:  P22: suction pressure < 0.07MPa. ...
Page 137 V8/V8i PRO VRF 50Hz Procedure P22/P25 Ensure th e following 2 points: 1. Th e stop valve has been opened 2. Th e Low pressure sensor is properly connected to the compressor module board Th e 2 points above is normal Correct and reconfirm Operating system and measure the low pressure...
Page 138 V8/V8i PRO VRF 50Hz 2.25 P24: Abnormal elevation of low pressure Digital display output Description ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger/ Recover condition ▪ Trigger condition: Suction pressure >1.6MPa and lasts 60 minutes ▪...
Page 139 V8/V8i PRO VRF 50Hz 2.26 xP32, xP33: No.(x) compressor high DC bus current protection Digital display output Description ▪ The DC bus current of No.x compressor is too high, triggering protection shutdown ▪ All units stop running.. ▪ Error code is displayed on the unit with the error. Trigger / recover condition ▪...
Page 140 V8/V8i PRO VRF 50Hz Procedure XP32，XP33 Open ODU stop ODU stop valve is closed? valve compressor cable is Replacing the damaged compressor Cable The resistance of The compressor is the compressor wiring damaged. Replace terminals to the ground is the compressor less than 1 MΩ...
Page 141 V8/V8i PRO VRF 50Hz 2.27 P51: High AC voltage protection Digital display output Description ▪ The AC voltage of the system is too high, triggering the protection shutdown ▪ All units stop running ▪ Error code is displayed on the unit with the error. Trigger / recover condition ▪...
Page 142 V8/V8i PRO VRF 50Hz 2.28 P52: Low voltage protection Digital display output Description ▪ The AC voltage of the system is too low, triggering the protection shutdown ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 143 V8/V8i PRO VRF 50Hz Procedure Check the power input: 1. Whether the input voltage is within the allowed range (±10%) 2. Whether the input power supply is phase missing or wiring error 3. Whether the three-phase input voltage imbalance is less than 12V Whether the power Repairing the input input is abnormal...
Page 144 V8/V8i PRO VRF 50Hz 2.29 P53: Phase B and N of the power cable are connected to the opposite protection Digital display output Description ▪ System zero line, phase line reverse connection ▪ All units stop running ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 145 V8/V8i PRO VRF 50Hz Procedure Whether there is any abnormality in Replace inverter the input voltage of the power supply of the control board inverter drive board [1] Whether the line connection is normal Ensure proper (Whether the connection is missed or the wiring screw is not tight) Whether the power supply...
Page 146 V8/V8i PRO VRF 50Hz 2.30 P54: DC bus low voltage protection Digital display output Description ▪ The DC bus voltage of the compressor is too low ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 147 V8/V8i PRO VRF 50Hz 2.31 P55: Dc bus ripple over protection Digital display output Description ▪ The ripple of the dc bus on the module is over the limits. ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 148 V8/V8i PRO VRF 50Hz Procedure Standby check whether the three- Rectify the power phase input power supply of the inverter drive supply board is missing phase or wrong phase Main relay of Standby measure whether L1L2 relay output Replace the Inverter inverter drive board is missing phase drive board...
Page 149 V8/V8i PRO VRF 50Hz 2.32 xP56: No.x inverter driver board DC bus voltage is too low Digital display output Description ▪ No.x inverter driver board DC bus voltage is too low ▪ All units stop running.. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 150 V8/V8i PRO VRF 50Hz 2.33 xP57: No.x inverter driver board DC bus voltage is too high Digital display output Description ▪ No.x inverter driver board DC bus voltage is too high ▪ All units stop running.. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 151 V8/V8i PRO VRF 50Hz 2.34 xP58: No.x inverter driver board DC bus voltage is seriously too high Digital display output Description ▪ No.x inverter driver board DC bus voltage is seriously too high ▪ All units stop running.. ▪ The error is displayed separately on each Outdoor Unit. Trigger / recover condition ▪...
Page 152 V8/V8i PRO VRF 50Hz 2.35 P71: Error in EEPROM Digital display output Description ▪ The EEPROM parameter of the ODU main control board is incorrect ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪...
Page 153 V8/V8i PRO VRF 50Hz 2.36 Pb1: HyperLink overcurrent error Digital display output Description ▪ HyperLink overcurrent error ▪ All units stop running. ▪ Error code is displayed on master ODU. Trigger / recover condition ▪ Trigger condition: No IDU is in power down mode and the feedback voltage of the HyperLink board is > 1.5V for 120ms. ▪...
Page 154 V8/V8i PRO VRF 50Hz Procedure Remove the ODU M1M2 communication The ODU mainboard continues to restart, and the LED3 ODU mainboard is cable and measure whether there is a short circuit on the right side of HyperLink board lights up damaged, replace it between the two communication cables Measure whether there is a short circuit...
Page 155 V8/V8i PRO VRF 50Hz 2.37 Pd1, Pd2: Anti-condensation protection Digital display output Description ▪ Anti-condensation protection ▪ All units stop running. ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪ Trigger condition: Pd1:The outlet temperature of Microchannel heat exchanger is below the dew point temperature for more than 10 minutes Pd2:Pd1 protection occurs 2 times in 60 minutes ▪...
Page 156 V8/V8i PRO VRF 50Hz Procedure Turn off the power supply, open the electrical control box to check the condensation of the radiator, and dry all water droplets on the radiator and inverter driver board. T5, T6A, and T6B sensors are Correct sensor installed in correct positions position...
Page 157 V8/V8i PRO VRF 50Hz 2.38 xb01: The electronic expansion valve is in error Digital display output Description ▪ No.x electronic expansion valve’s connection on main control board is missing(1 to 4 correspond to expansion valves A, B, C, and E respectively) ▪...
Page 158 V8/V8i PRO VRF 50Hz Procedure xb01 No.x electronic expansion valve s connection on Ensure the connection is main control board is missing correct and firm. or loose[1] Electronic expansion valve main control coil has malfunction [2] board is damaged Replace the main Replace the electronic control board expansion valve...
Page 159 V8/V8i PRO VRF 50Hz 2.39 U11: Outdoor unit model is not set Digital display output Description ▪ All units stop running ▪ Error code is displayed on the unit with the error Trigger / recover condition ▪ Trigger condition: The model information is not set. ▪...
Page 160 V8/V8i PRO VRF 50Hz 2.40 U12: Outdoor unit Capacity setting error Digital display output Description ▪ The capability information of outdoor unit is not set ▪ All units stop running ▪ Error code is displayed on the unit with the Error Trigger / recover condition ▪...
Page 161 V8/V8i PRO VRF 50Hz 2.41 U21: The indoor unit connection is incorrect Digital display output Description ▪ The indoor unit connection is incorrect ▪ All Outdoor units stop running ▪ Error is only displayed in main control board Trigger / recover condition ▪...
Page 162 V8/V8i PRO VRF 50Hz 2.42 U31: The test run was never successful Digital display output Description ▪ The test run was unsuccessful ▪ All units stop running ▪ Error code is only displayed on the master unit. Trigger / Recover condition ▪...
Page 163 V8/V8i PRO VRF 50Hz 2.43 U32, U33, U34: The temperature is not suitable for test run Digital display output Description ▪ Ambient temperature is out the allowed range of test run ▪ All units stop running ▪ Error code is only displayed on Outdoor Unit Trigger /Recover condition ▪...
Page 164 V8/V8i PRO VRF 50Hz Procedure U32\U33\U34 Check whether the ambient temperature is within the allowed range Termination of test run of test operation Power it on again and Rest runt in 30 minutes Troubleshooting...
Page 165 V8/V8i PRO VRF 50Hz 2.44 U35, U37: Stop valve is not open Digital display output Description ▪ Stop valve is not open ▪ All units stop running ▪ Error code is only displayed on the master unit. Trigger/ Recover condition ▪...
Page 166 V8/V8i PRO VRF 50Hz Digital display output Description ▪ There are indoor unit in the communication system outside the refrigerant system. ▪ All units stop running ▪ Error code only displayed on the master unit. Trigger / Recover condition ▪ Trigger condition: There are indoor unit in the communication system outside the refrigerant system. ▪...
Page 167 V8/V8i PRO VRF 50Hz Digital display output Description ▪ During the test run, abnormal changes in ambient temperature are detected and the operation is stopped. ▪ All units stop running ▪ Error code only displayed on the master unit. Trigger / Recover condition ▪...
Page 168 V8/V8i PRO VRF 50Hz Reinstall according to the Check whether the ventilation INSTALLATION AND and heat dissipation are good and meet installation requirements OWNER S MANUAL Remove other ODUs or Check whether return air heat sources, or transfer of the ODU is affected by other the machine to a well- heat sources or ODUs cooled environment for...
Page 169 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The ODU in changeover mode doesn’t detect the signal of VIP IDU. ▪ ODUs stop running ▪ Error code only displayed on the master unit. Trigger / Recover condition ▪ Trigger condition: ①The ODU in changeover mode , but the VIP address has not been set.
Page 170 V8/V8i PRO VRF 50Hz Digital display output Description ▪ Protection Overconnection ratio ▪ All units stop running Trigger / Recover condition ▪ Trigger condition: Code of Indoor Unit and type analysis Code of Indoor Unit Indoor Unit Indoor Unit Indoor Unit Indoor Unit Type of Indoor Unit VRF Air-cooled indoor...
Page 171 V8/V8i PRO VRF 50Hz Indoor/Outdoor Unit connection rate out of allowable range Procedure Check the indoor unit connection and remove the indoor unit beyond the permitted range Power on and check again Troubleshooting...
Page 172 V8/V8i PRO VRF 50Hz 2.49 U51: Outdoor unit of Individual Series is installed in combine system Digital display output Description ▪ Outdoor unit of Individual Series is installed in combine system ▪ All units stop running ▪ Error code is only displayed on master unit. Trigger / Recover condition ▪...
Page 173 V8/V8i PRO VRF 50Hz 2.50 U53: Detected different series outdoor units in the same VRF system Digital display output Description ▪ Detected different series outdoor units in the same VRF system ▪ All units stop running ▪ Error code is only displayed master unit Trigger / Recover condition ▪...
Page 174 V8/V8i PRO VRF 50Hz 3 Error in Compressor Driver 3.1 xL1E: Hardware overcurrent Digital display output Description ▪ The current exceeds the OCP protection value (peak value) set by the hardware or the IPM module receives an FO signal ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again Trigger / recover condition (1)Current reaches OCP protection value:...
Page 175 V8/V8i PRO VRF 50Hz Procedure xL1E Replace the inverter driver Failure during standby board Compressor windings short-circuit Replace the compressor between phases Replace inverter diver board , Troubleshooting and the error code disappear abnormal sound or Check whether indoor unit Replace the indoor unit shaking in compressor electronic expansion valve can...
Page 176 V8/V8i PRO VRF 50Hz 3.2 xL11, xL12 : Software overcurrent Digital display output Description ▪ The current exceeds the OCP protection value set by the software. ▪ The compressor will shutdowm when the error occurs. If the error disappears one minute later, the compressor will start again.
Page 177 V8/V8i PRO VRF 50Hz 3.3 xL2E: Module overtemperature protection Digital display output Description ▪ The temperature of the IPM exceeds 105° C. ▪ The compressor will stop when the error occurs. If the error disappears one minute later, the compressor will start again Trigger / recover condition ▪...
Page 178 V8/V8i PRO VRF 50Hz 3.4 xL3E: The bus voltage is too low Digital display output Description ▪ Bus voltage is lower than the low bus voltage protection threshold set by the software (350VDC). ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again.
Page 179 V8/V8i PRO VRF 50Hz 3.5 xL31: The bus voltage is too high Digital display output Description ▪ Bus voltage is higher than the high bus voltage protection threshold set by the software (800VDC). ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again.
Page 180 V8/V8i PRO VRF 50Hz 3.6 xL32: The bus voltage is excessively high Digital display output Description ▪ Bus voltage is higher than the high bus voltage protection threshold set by the software (820VDC). ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again.
Page 181 V8/V8i PRO VRF 50Hz Digital display output Description ▪ Bias calibration of the current sampling circuit is in error.ias calibration of the current sampling circuit is in error. ▪ After this error occurs, the compressor cannot start. Check whether the inverter driver board is in error. Trigger / recover condition ▪...
Page 182 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The compressor fails to start ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again. Trigger / recover condition ▪ Trigger condition:The compressor fails to start ▪...
Page 183 V8/V8i PRO VRF 50Hz Digital display output Description ▪ The compressor is blocked. ▪ The compressor stops running after the error occurs. If the error disappears one minute later, the compressor starts again. Trigger / recover condition ▪ Trigger condition:The compressor is blocked. ▪...
Page 184 V8/V8i PRO VRF 50Hz 4 Error in Fan Drive 4.1 xJ1E: Hardware overcurrent Digital display output Description ▪ The current exceeds the OCP protection value (peak value) set by the hardware or the IPM module receives an FO signal ▪ The fan stops running after the error occurs. If the error disappears five seconds, the fan starts again Trigger / recover condition (1)Current reaches OCP protection value: ▪...
Page 185 V8/V8i PRO VRF 50Hz 4.2 xJ11, xJ12: Software overcurrent Digital display output Description ▪ The current exceeds the OCP protection value set by the software. ▪ The fan will stop when the error occurs. If the error disappears five seconds later, the fan will start again. Trigger / recover condition ▪...
Page 186 V8/V8i PRO VRF 50Hz 4.3 xJ2E: Module overtemperature protection Digital display output Description ▪ The temperature of the IPM exceeds 105°. ▪ The fan stops running after the error. If the error disappears after five seconds, the fan starts again. Trigger / recover condition ▪...
Page 187 V8/V8i PRO VRF 50Hz 4.4 xJ3E: The bus voltage is too low Digital display output Description ▪ Bus voltage is lower than the low bus voltage protection threshold set by the software (350VDC). ▪ The fan stops running after the error occurs. If the error disappears five seconds later, the fan starts again. Trigger / recover condition ▪...
Page 188 V8/V8i PRO VRF 50Hz 4.5 xJ31: The bus voltage is too high Digital display output Description ▪ Bus voltage is higher than the high bus voltage protection threshold set by the software (800VDC). ▪ The fan stops running after the error occurs. If the error disappears five seconds later, the fan starts again. Trigger / recover condition ▪...
Page 189 V8/V8i PRO VRF 50Hz 4.6 xJ32: The bus voltage is excessively high Digital display output Description ▪ Bus voltage is higher than the high bus voltage protection threshold set by the software (820VDC). ▪ The fan stops running after the error occurs. If the error disappears five seconds later, the fan starts again. Trigger / recover condition ▪...
Page 190 V8/V8i PRO VRF 50Hz 4.8 xJ5E: Startup failed Digital display output Description ▪ The fan fails to be started. ▪ The fan stops running after the error. If the error disappears after five seconds, the fan starts again. Trigger / recover condition ▪...
Page 191 V8/V8i PRO VRF 50Hz 4.9 xJ52: Locked-rotor protection Digital display output Description ▪ The fan is blocked. ▪ The fan stops running after the error. If the error disappears after five seconds, the fan starts again. Trigger / recover condition ▪...
Page 192 V8/V8i PRO VRF 50Hz 4.10 xJ6E: Motor lack of phase protection Digital display output Description ▪ The fan has phase loss protection. ▪ The fan stops running after the error. If the error disappears after five seconds, the fan starts again. Trigger / recover condition ▪...
Page 193 V8/V8i PRO VRF 50Hz 5 Appendix 5.1 Resistance characteristics of temperature sensor Table 6-5.1: Temperature probe symbol and position Temperature probe symbol and position The probe type Bottom of heat exchanger Type A Outdoor ambient temperature Type A Liquid pipe stop valve Type A Microchannel heat exchanger inlet pipe Type A...
Page 194 V8/V8i PRO VRF 50Hz (continues) Table 6-5.2: Temperature sensor temperature resistance characteristic table temperature resistance (kΩ) (°C) Type A Type B Type C 33.33 171.9 169.9 31.56 163.3 161.5 29.91 155.2 153.6 28.35 147.6 146.1 26.88 140.4 139.1 25.5 133.5 132.3 24.19 127.1...
Page 195 V8/V8i PRO VRF 50Hz (continues) Table 6-5.2: Temperature sensor temperature resistance characteristic table temperature resistance (kΩ) (°C) Type A Type B Type C 4.387 24.85 24.85 4.213 23.89 23.9 4.046 22.89 22.98 3.887 22.1 22.1 3.735 21.26 21.26 3.59 20.46 20.47 3.451 19.69...
Page 196 V8/V8i PRO VRF 50Hz (continues) Table 6-5.2: Temperature sensor temperature resistance characteristic table temperature resistance (kΩ) (°C) Type A Type B Type C 0.9366 5.488 5.492 0.9075 5.32 5.322 0.8795 5.157 5.159 0.8525 0.8264 4.849 4.855 0.8013 4.703 4.705 0.7771 4.562 4.566 0.7537...
Page 197 V8/V8i PRO VRF 50Hz (continues) Table 6-5.2: Temperature sensor temperature resistance characteristic table temperature resistance (kΩ) (°C) Type A Type B Type C 0.2777 1.632 0.2708 0.2641 0.2576 0.2513 0.2451...
Page 198 V8/V8i PRO VRF 50Hz 5.2 Normal status parameter of refrigerant system The parameters listed in Tables 5.2.1 and 5.2.2 need to be noted when the following conditions are met:: ▪ The master can detect all indoor machines: ▪ The number of indoor units displayed for outdoor units is consistent with the actual installation. ▪...
Page 199 V8/V8i PRO VRF 50Hz 5.3 Analysis of the cause of system anomalies Cause Analysis of Excessive discharge Temperature Check whether coil is not failure of SV7 coil properly installed failure of SV7 body Control failure of Control failure of mainboard Check whether coil failure of EEVC coil is normal...
Page 200 V8/V8i PRO VRF 50Hz Cause Analysis of too high Pressure Stop valve is closed Check the stop valve The resistance of the Piping is bent or severely Check the pipe high-pressure side pipe deformed is too large Check whether there is a large temperature difference The pipe is blocked.
Page 201 V8/V8i PRO VRF 50Hz Cause Analysis of too Low Pressure Whether there is a big difference Failure of low Control failure of between the actual low pressure pressure sensor The compressor and the spot low pressure *cooling mode Check whether the power supply of capacity Mainboard is the mainboard is abnormal...
Page 202 V8/V8i PRO VRF 50Hz 5.4 Outdoor unit main Control Board ports table Figure 6-5.1: Outdoor unit main Control Board ports...
Page 203 V8/V8i PRO VRF 50Hz Table 6-5.5: Main Control Board port definition Table Label in Figure Port code Content Port voltage 5-2.1 CN82 Reserved 5Vdc CN36 Recirculation fan control port 3.3Vdc CN70 EEVA drive port 12Vdc CN71 EEVB drive port(Reserved) 12Vdc CN72 EEVC drive port 12Vdc...
Page 204 V8/V8i PRO VRF 50Hz 5.5 Compressor & Fan drive board ports detection Port reference and function definition of Compressor & Fan drive board Figure 6-5.2: Compressor & Fan drive board ports Table 6-5.5: Port definition and functions table Label in Port Feature Content...
Page 205 V8/V8i PRO VRF 50Hz Table 6-5.5: Port definition and functions table (continues) Label in Port Feature Content Port voltage Figure 6-2.5 code identifier Power supply terminal for DC fan drive board (P,N) 438Vdc~650Vdc(Rated 540Vdc; CN38 (Reserved） P is positive, N is negative) CN26 Fan module controls power supply(Reserved）...
Page 206 V8/V8i PRO VRF 50Hz Fan drive board Figure 6-5.3: Fan drive board Table 6-5.6: Compressor & Fan drive board port Label in Port code Content Port voltage Figure 5-2.5 Fan module controls power supply(Reserved） EEPROM Program burning port Communication port between main control board and CN4\CN1 Fan drive board Power supply terminal for DC fan drive board (P,N)
Page 207 V8/V8i PRO VRF 50Hz Inverter drive board measurement guidelines Please give priority to the following things before testing Inverter drive board: Cut off the power supply: To avoid electric shock from capacitor discharge, power off for 10 minutes and wait for capacitor discharge before operation: Remove all wiring on the Inverter drive board.
Page 208 V8/V8i PRO VRF 50Hz Schematic diagram of measuring points of Inverter drive board:...
Page 209 V8/V8i PRO VRF 50Hz 5.6 Appendix of Pressure Sensor Detection Pressure sensor characteristics 5.00 High Pressure sensor P Low Pressure sensor P 4.50 y = 2x + 0.5 y = 0.87x + 0.5 4.00 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 Pressure（MPa)
Page 210 V8/V8i PRO VRF 50Hz 5.7 Refrigerant volume diagnosis When running the refrigerant quantity detection program, the machine calculates the system refrigerant quantity according to the ambient temperature, condensing temperature and evaporation temperature, heat exchanger inlet and outlet temperature and other parameters, and give hints according to the results The detection results of the system have V6 IDUs may have a large deviation.
Page 211 Procedure Start Confirm whether the following two points meet the requirements: 1. Whether all IDUs in the system are V8 series? 2. Does the system choose V8 communication protocol or HyperLink? Whether the above two The detection results of the system have...
Page 212 V8/V8i PRO VRF 50Hz 5.8 Oil volume table Table 6-5.6: V8 Oil volume table Compressor Compressor Total additional adding Oil model TOTAL OIL TOTAL OIL A (Y1) B (Y2) compressors oil oil Volume FV68H 1.1L 1.1L 5L+1.1L 6.1L 10HP FV68H 1.1L 1.1L 5L+1.1L...
Page 213 Ver. 2023-2 Midea Building Technologies Division Midea Group Add.: Midea Headquarters Building, 6 Midea Avenue, Shunde, Foshan, Guangdong, China Postal code: 528311 mbt.midea.com / global.midea.com/tsp.midea.com Note: Product specifications change from time to time as product improvements and developments are released and may vary from those in this...

This manual is also suitable for:

V8 pro series V8i pro series Mv8-252wv2rn1e Mv8-280wv2rn1e Mv8-335wv2rn1e Mv8-400wv2rn1e ... Show all

Midea V8 Series Service Manual

Table of Contents

Part 3 Control

Wiring Diagrams

Quick Links

Chapters

Related Manuals for Midea V8 Series

Summary of Contents for Midea V8 Series

This manual is also suitable for:

Table of Contents